Teko M3RINO.XC Midweight Hiking Socks, Della, Medium 74% Merino Wool / 25% Nylon / 1% Elastic Made in US 74% organic merino wool, 23% nylon, 3% Lycra Spandex Designed for hiking, backpacking, snowshoeing and cold-weather everyday wear. Organic, undyed, chlorine-free Merino wool is naturally wicking and insulating. Recommended for all weather conditions. Machine Washable Made In USA